Method of making tire-valve stems and the like



Sept. 11, 1928.

E. G. OAKLEY METHOD OF MAKING TIRE VALVE STEMS AND THE LIKE Filed March 12, 1923 s Sheets-Sheet 1 Villa/Ill!!! Patented Sept. 11, 1928.

* UNITED sTA'rss ea'reur OFFICE.

ERASTUS G. OAKLEY, OF SOUTHIPORT, CONNECTICUT, ASSIGNOR, TO BRIDGEIORT BRASS COMPANY, OF BRIDGEPOELT, COENECT ICUT;

METHOD OF MAKING TIBE-VALVE AND THE LIKE.

Application filed March 12 ldhisinvention relates to the manufacture of so-called valve stems or casings, and more particularly to a valve stem designed for use with pneumatic tires, the invention being particularly concerned with the tube or casingin which the valve proper is mounted. In the past, such stems or casings have been manufactured from apiece of solid bar stock. After such a blank has been headed to provide the broad disc-like base, commonly formed upon one end of the stem, usually the next operation is to drill an opening through the entire length of the blank, in order to provide for the admission of air to the tire, after the stem has been cannected therewith. For various reasons, a valve stem made by this prior method possesses certain inherent defects and disadvantages, among which are lack of tensile strength, aweak point of connection between the body of the stem and the broadened base portion, and a relatively large wastage of material and lack of economy in the process of manufacture. ln order to permit the drilling of the long opening through the blank, it is necessary to use a considerable amount of lead, in the alloy of which the piece of bar stock is composed, and this results in a lessening of the tensile strength of the material. Also, when a piece of solid stock is headed, a considerable flow of metal is necessary in the central part of the head. This causes a hardening of the metal at this point. which renders it more or less brittle and, therefore, more easily broken.

In my improved process, the valve stem is made from a piece of tubular stock, the original tube opening being, retained during the process of manufacture, so that the long drill-v 'ing operation, necessary in past methods, is dispensed with. Moreover, in heading; a piece of tubular stock. the wall of the tube can be folded upon itself in such a way that much less flowing of the metal is necessary to accomplish the heading operation, and the material is not rendered brittle and hard. It will also be obvious that my method is more economical, in that there is little wastage of material, and the operations required are more or less simple and may be performed at relatively small expense by machine work.

One object of my invention, therefore, is

to obviate thedisadvantages noted above in prior process, and producea valve'stem which 7 claimed.

, 1922. Serial No. 624,532.

shall possess greater tensile strength than J. l

tllOSB heretofore made, and which will, at the same time, be economical to manufacture.

Anotb er object of my invention is the provision of a valve stem which may be made cheaply and without undue wastage of material, and which will, at the same time, possess all of the advantages of, and be superior than the methods heretofore used, and which will. produce an article of superior quality;

fothese and other ends, the invention consists 1n the novel features and combinations of steps to be hereinafter described and In the accom iiauying drawings:

Fig.1 isa side elevational view of a valve stem embodying my improvements; I

Fig. 2 is an enlarged sectional view of the same; I I

Fig. 3 is-a top plan view of thevalve stem shown in Fig.- 2;

Fig. 41 com-prises two side elevational views, taken at right angles to each other, of a piece of flat-sided tubular stock, from which the valve stem is made by my improved method, and an end view thereof; I

Fig. 5 is a view showing one of the heading operations:

6 is a view similar to Fig. 5, showing the completion of the heading operation;

Fig. 6 is a fragmentary view of a punch of modified form.

Fig. 7 is an elevational view, partly in section, showing the rolling operation by which the annular, inwardly extending displacetools by which the end of the blank is reduced in diameter by a series of swaging operations, looking in the direction of the arrows 101O on Fi 11.

' 11 is a sectional view online 11-11- of Fig. 10;

Fig. 12 is an elevational view, showing the F 10 is an elevational view, showing the.

necking operation, by which the annular re- .cess is cut in the body of the stem, adjacent the base.

The particular valve stem which I have shown in the drawings, as produced by my improved method, comprises a tubular body portion provided withfiat sides 11, and

joining a relatively broad disc-like base 12 by a reduced portion or neck 13, formed by an annular exterior groove upon the body portion ad acent the base.

the provision of an annular shoulder at this point, which shoulder is designed to seat the spring holder of a common type of tire valve (not shown). Adjacent the upper reduced end, the tube opening is bored out to provide a seat 17, usually in the shape of a frustum of a cone, for a valve seating member, and above this seat, the bore is threaded, as at 18, to pro Vide for thesecuriug of the valve withln the stem.

Accordingto the preferred embodiment of my method which I have chosen to illustrate and describe, the valve stem is formed from a tubular piece of stock, as shown at 20 in Fig. 4, provided with the flat sides 21. After a proper length of this stock has been cut off from a long tube, the length is headed up by any desired method, in order to provide the base portion, shown at 12 in Fig.1. I prefer to perform this heading operation by means of a heading press, such as shown in Figs. 5 and 6, althoughit will be obvious that the particular tools employed are not of importance in all aspects of the invention. The pressshown may be termed ;a double-stroke header press, and comprises a die bed 22 supporting a die provided with a the opening 24, having a counter-sunk portion 25 at the upper surface of the die.

To the "ram 26am secured the two punches 27 a and 28, which are. brought down successlvely upon the blank to perform the completeheading operation. The blank is placed in the die opening 24, where it will seat upona shoulder 29 in the lower portion of the die opening, and

. the punch 27 is brought down upon'its upper 5, and at the second stroke of the press, which end. The wall of the tube at this end will be doubled over to some extent, as shown in Fig.

operates tobring the punch 28 down upon the work, the heading operation will be com- 7 Y pleted, as shown 111 Fig. 6. 00

v The counter-sunk portion 25 of the die 1S provided. with annular serrations of grooves 30'to form complemenstem.

tary serrations 31 in the base of thevalve These heading operations serve also to thicken the tube wall adjacent the base, as

shown at 32 in Fig. 6,whieh, as will be experformed may be varied without departing from the principles of the invention, I prefer to form the shoulder or annular projection 16 after the blank has been headed. While this operation may be performed in other ways, I have chosen to illustrate, for this purpose, a rolling press, shown in a fragmentary way in Fig. 8, consisting of a pair of opposing dies 35 and 36, having the ribs 37 and 38 formed thereon. As shown in Fig. 7, the headed blank is placed between these two dies in a vertical position, the end of the blank opposite the head being supported upon the bed 39 of the machine. p The die 36 is then given a sliding reciprocatory motion relative to the die 35, which results in an annular channel or groove being rolled into the exterior surface of the blank by the ribs 37 and 38, as shown more particularly at 40 in Fig. 7,. It will be seen that this operation results in the entire wall being displaced inwardly at this point, so that an annular projection or shoulder is formed in the tube bore, corresponding with the annular groove upon the exterior thereof.

' In order to have a substantially smooth ex terior surface, which is desirable upon the finished article, it is now necessary toclose up the groove, which has been formed by the operation just described,and for this purpose, the blank'may be placed upon a die 41, resting upon the bed 42 of a die press, with which a punch 43 is adapted to cooperate. The body of the blank may be surrounded by a sleeve 44, in order to prevent any distortion of the blank, and the punch 43 is brought down upon the base 12. As shown in Fig. 9, this operation results in the closing together of the walls of the groove 40, with ;the resultthat the exterior surfaceof the body of the blank is substantially continuous and smooth, the annular projection, however, still remaining within the tube bore. Preferably, the length of the sleeve 44 is such that when the punch 43 is at the downward limit of its stroke, there will be a slight clearance between the lower surface of the base 12 and the upper end face of the sleeve, so that the configuration of this face of the base will not be changed. The blank may then be.removed from the press by means of the knock-out punch 45. 7

It is now necessary to reduce the exterior diameter of the blank adj acent theupper end thereof, and a preferred method of accomplishing this result is bymeans of successive swaging operations, illustrated in Figs. 10 and 11 of the drawings. The particular swaging machine shown consists of a pairof reciprocably mounted swaging dies 47 and 48 slidable in guides 49 and 50, and provided with complemental openings or seats shown at 51, 52, and 53, these openings being progressively smaller indiameter, so that the end of the blank will be progressively reduced in size as it is passed from one opening to the next. The dies may be brought together or reciprocated by any preferred means, and within the opening 51 may be provided a stop 54 to limit the insertion of the blank therein. Such a limiting means will not be necessary in the remaining die. openings, as

- the shoulder, formed on the blank by the first swagmg operation, will serve to limit its entrance into the succeeding openings. During this operation the blank may rest upon openings 55 in the frame of the machine.

The neck 13 may be provided by forming an annular recess upon the exterior of the stem body adjacent the base, by means of a suitable milling or cuttingtool 56, shown more or less diagrammatically in F 12. It

will be noted from an inspection of Fig. 2," that due to the thickening of the wall during the heading process, sufficient metal may be cut away to provide this neck without diminishing the thickness of the wall at this point, beyond'thatof the rest of the tube. In other words, notwithstanding the fact that the ex terior diameter of the. tube is reduced at this point, the wall is of substantially the same thickness as that of the remainder of the tube, due to the reduction of the tube bore during the heading operation.

Due to the fact that the tube bore at the upper end of the stem body has been considerably reduced in diameter during the swaging operation, illustrated in Figs. 10 and 11 of the drawings, it necessary to enlarge this 0 )enin b a drillin or borin o aeration in order that it may be sufiiciently large to, re.- ceive the usual tire valve. This operationmay now be broughtabout in any of the usual well known ways, and the seat 17 provided for the valve seat member. The bore just de-' scribed is then threaded interiorly, as at 18,

and the exterior threads 14 are out upon the reduced end of the stem, thus completing the process of manufacture and thestem is ready for use. K

in Fig. 6*, I have shown a punch 6.0-of modified form which may, ifdesired, be used in place of the punch 28 to complete the heading'operation. This punch is provided with a pin 61 which, when the punch is brought down upon the tube, enters the tube bore and positively preserves the tube opening by preventing the metal from being caused to flow inwardly at this point to a sufiicient extent to close the opening. When the punch 28 is used, which punch is not provided with a centering pin, the opening through. the tube is preserved by gauging the length of the upper end of the tube, which projects from the openings in the die 23 to beat-ted upon and folded by the punches 27 and 28. It will be obvious that if the proper amount of metal is left to project from the die, a satisfactoryand strong head may be formed uponthe blank, without entirely closing the opening in this head. However, when the punch is used. the length of the tube which projects from the die opening need not be so carefully gauged, astlie pin 61 will prevent the closing of this opening, and will force outwardly into the tube head any metal which would other-' wise tend to flow inwardly to close the opening.

It will be apparent that my improved process for the manufacture of articles such as de scribed consists of comparatively few operations, which may be cheaply performed, and results in an article which is superior to that manufactured by prior methods. While I have shown and described a preferred method of carrying out my invention, it will be understood that the same is not to be'limited to all the details shown, or to the precise steps described, or to the means described for carrying out the various steps, but,on the other hand, the method is capable of modification and variation without departing from the spirit of the invention or from the scope of the appended claims.

lVhat I claim is: Y i

1. The process of nlaking a valve stem or like article, which comprises folding over a wall of a blank in the form of a piece of tubu-f lar stock of uniform diameter throughout its length adjacent one end thereof to form atlat disklike head and simultaneously flowing the metal of the blank inwardly adjacent the head to form a thickened wall, while limiting the movement of the metalinto the bore of the blank to preserve the opening therethrough.

2. The process of making a valve stem or like article, which comprisesfolding over the wall of a blank in the form of a piece of tubui lar stock of uniform diameter throughout its length, adjacent one end thereof, to form a flat disc-like head, while preserving the tube opening in said headed portion, and reducing the exterior diameter of the other end of the blank to form an upper neck.

, 3. The process of making avalve stem oi the like, which comprises forming a flat disle like head upon a blank in the form of a piece of tubular stock of uniform diameter throughout'its length by folding over upon itself the wall. adjacent one end thereof 7 against a stop member within the bore of the blank, so as to prevent the closing of the bore during the heading operation, and simultaneously flowing the metal of the blank inwardly adjacent the head to form a thickened portion at this point.

' displacing the metal of the stem inwardly at an intermediate point to form an interior annular shoulder. v

5. The method of making a valve stem or the like from a piece of tubular stock, which comprises forming a flat disk-like head on said stem and flowing the metal adjacent the head to thicken thetube wall, and then cutting an annular recess in the stem at thepoint so thickened. i i 6. The method of making, from a piece of tubular stock, a valve stem or the like, having a disc-like head joining the stem body by a narrow neck, which comprises thickening interiorly the wall. of the tube ad acent the head, and then cutting an exterior annular recess. at the point so thickened.

7. The method of making a valve stem or the like, which comprises cutting from a piece of flat-sided, tubular stock a blank of the desired length, and forming a circular, disk-like base on one end of the blank by folding over the Wallthereof against a stop member in the bore of the blank inward movement of the metal of the wall.

8. The method of making a valve stem or the like, which comprises heading one end of a piece of tubular stock and simultaneously thickening the tube wall adjacent the formed head, and then cutting an exterior groove in the blank at saidthickened por tion.

9. The method ofv making a valve stem or the like, which comprises heading one end of a piece of tubular stock and simultaneously thickening the tube wall adjacent the formed head by an inward flowing of the metal at this point, and; then cutting an annular exterior groove upon said thickened portion of the blank.

10. The method of making a valve stem or the like from a piece of tubular stock, disk-like which comprises forming a flat head on said stock and displacing inwardly the wall adjacent the head, in order to thicken the wall at this point, and, at the same to limit the time, preserving the tube opening at the point so thickened, and then cutting an exterior groove at the thickened portion of the wall. i 11. The method of making a valve stem or the like, which comprises displacing inwardly the wall of a piece of tubular stock, by forming an external, annular groove therein, and then closing together the walls of said groove.

12. the like, which comprises displacing inwardly the .wall of a piece of tubular stock by forn'i'ing an external, annular groove therein,

and then placing said blank in a suitable sleeve to prevent the distortion thereof, and closing together the walls of said groove by applying pressure to opposite ends ofthe blank. 1 i

13. The method of making a valve stem or the like, from a piece of tubular stock, which comprises folding over upon itself the wall adjacent one end thereof against a stop member within the bore of the blank to form a disk-like head, while simultaneously flowin g the metal of the blank inwardly adjacent the head to form a thickenedportion, forming an annular groove in the portion sothick ened, displacing the tube wall inwardly at a point intermediate the ends of a blank to form an annular interior shoulder, and displa-cingthe tube wall inwardly at one end of Itheiblank to reduce the exterior dimensions thereof, saidlast named displacement also causing a reduction in the diameter of. the tube bore, at that end thereof, and then enlarging the tube bore'atv this point for, the purpose described.

li. The method of making a valve stem which comprises displacing the wall at one end of a tube to form an integral head, forming an exterior groove in the tube intermediate its ends, so as to create an inwardly projecting shoulder fol-seating a valve spring, and compressing the blank to close up, at least partially, the exterior groove.

15. The. method of making a valve stem which comprises displacing the wall at one end ofa tube to form an integralhead, forming an exterior groove in the tube intern' ediate its ends, so as to create an inwardly projecting shoulder for seating a valve spring, and compressing the blank to close up, at least partially, the exterior groove, and

reducing the upper end of the blank by swag ing. a V

a In witness whereof, I have hereunto'set my hand on the 21st day of February, 1923.

' ERASTUS, G. OAKLEY.

The method of making a valve stem or Y 

